1. Field of the Invention
The present invention relates generally to a mobile telecommunication system, and in particular, to a method of providing a high-speed packet data service according to various traffic characteristics.
2. Description of the Related Art
A Code Division Multiple Access (CDMA) 1x system has evolved from a typical 2nd generation (2G) CDMA system. It offers wireless data service at up to 144 Kbps, 129.6 Kbps faster than the 14.4 Kbps provided by the 2G CDMA system. In addition, voice service is also provided. A CDMA2000 Evolution-Data Only (1xEV-DO) system was proposed as a complementary solution for high-speed data transmission at the level of International Mobile Telecommunications (IMT)-2000. The CDMA2000 1xEV-DO system assigns overall system resources only to a data service, thus making high-speed data transmission at the Mbps level possible. This system supports packet-based communication rather than circuit-based communication.
FIG. 1 is a block diagram illustrating an example of a 7-layer protocol stack for wireless communication in a conventional CDMA2000 1xEV-DO system. As illustrated, the protocol stack comprises an application layer, a stream layer, a session layer, a connection layer, a security layer, a Media access Control (MAC) layer, and a physical layer.
The application layer processes actual data in an available form for users and uses the stream layer to transmit/receive the data streams. The stream layer generates and analyzes a stream header according to a service type supported by the application layer. An example of service types identified by stream headers is illustrated in FIG. 2. Referring to FIG. 2, four data stream types are distinguished by 2-bit values of the stream header.
More specifically, ‘0x0000 (default signaling application)’ indicates signaling data between an Access Terminal (AT) and an Access Network (AN), ‘0x0001 (default packet application bound to the radio access network’ indicates data used for AT authentication in a radio access network (RAN), ‘0x0002 (default packet application bound to the service access network)’ indicates actual data bound to a packet data network (e.g., Internet), and ‘0x0003 (TAS: Test Application Specification)’ indicates data defined for checking a system function.
As illustrated in FIG. 2, actual data is considered to be one type (0x002) in the stream layer. Considering that the application layer is capable of processing a variety of service packets, for example, File Transfer Protocol (FTP) packets, Voice over Internet Protocol (VoIP) packets, and video stream packets, servicing those different packets with the same traffic characteristics is inefficient. For example, VoIP packets and video stream packets are very sensitive to delay, and FTP packets are more sensitive to errors than to delay. Despite these different traffic characteristics, the stream layer handles the packets indiscriminately. Therefore, the user demand for discriminate services cannot be satisfied.
As described above, the CDMA2000 1xEV-DO system classifies all user data as one type and makes no distinction between the traffic characteristics of different packets including FTP, VoIP, and video stream packets, when servicing different packets. Therefore, there is a need for a method of providing various services for one call connection.